The present invention relates to the field of control systems for actuating optical elements.
Electrically controlled movable optical elements such as tip-tilt mirrors are often employed for telescopic tracking or viewing of various objects. In accordance with the prior art, a substantial plurality of mirror actuators are affixed to one side of a mirror to be pointed in various directions. The actuators move the mirror by different amounts so that the mirror as a whole points in a given selected direction, and such amounts are proportional to electrical control signals applied to the input circuits of the actuators. Since there are many actuators affixed to the movable mirror, numerous control voltages are applied to the actuators to cause a given selected mirror orientation. This means that a large number of control voltages which differ from one another must be generated, and a number of drivers equal to the number of actuators are provided to apply the different control voltages to the actuators.
It is an object of the present invention to sharply reduce the number of different control voltages to be applied to the array of mirror actuators, thereby to reduce the number of control voltage drivers, and the complexity of the electrical control system.